Chewing gum is a mixture of one or more polymeric materials, usually blended with one or more additional ingredients such as bulking agents, plasticizers, sweeteners and/or flavorants. The physical properties that make these components effective in a chewing gum also contribute to the difficulty of manufacturing and packaging the chewing gum. For instance, the polymeric material is often sticky, particularly at the temperatures above ambient to which the material is heated during mixing of the various ingredients. The gum is still quite sticky during rolling of the gum bulk into flat sheets from which the well known sticks are manufactured. Ingredients used as bulking agents, plasticizers, flavorants and/or sweeteners are often sticky as well. Furthermore, many of such ingredients are hygroscopic, that is, they exhibit a tendency to absorb water vapor from the atmosphere which in turn adds to the stickiness of the chewing gum during its manufacture and packaging.
It is known to employ powder, sometimes known as dusting powder or rolling powder, to attempt to alleviate the drawbacks caused by the stickiness of the chewing gum during its manufacture and packaging. That is, after the various components are heated and mixed together, the mass of gum is fed through an extruder, which forms it into a continuous sheet. The rolling powder is then deposited on the planar surfaces of this flat sheet before it is fed through a rolling machine, which reduces the thickness of the gum sheet to that of the finished sticks.
The rolling powder inhibits adhesion of the chewing gum to rollers and other equipment with which it comes into contact, which is very useful in that during commercial manufacturing operations the sheet is moving through the associated machinery at many dozens of feet per second. In addition, the rolling powder inhibits adhesion of the gum to the machinery which subsequently cuts the gum into sticks and packages it, and also inhibits adhesion of the gum to the wrapper with which the gum would otherwise come into contact.
Examples of rolling powders and their use are disclosed in, for instance, U.S. Pat. No. 4,208,432; U.S. Pat. No. 5,145,696; U.S. Pat. No. 4,374,858; and U.S. Pat. No. 4,976,972.
Rolling powders, however, can also contribute a number of drawbacks. Principal among these is the effect of the rolling powder on the taste of the final chewing gum product. Another drawback is the effect on the mouth feel of the gum when it is chewed, particularly if the rolling powder makes the gum feel dry or gritty in the mouth. In addition, rolling powders can accumulate in the processing machinery if it is not sufficiently adherent to the surface of the chewing gum. Moreover, the rolling powder represents an additional ingredient of the gum and as such can raise the cost of manufacture to unacceptable levels if the component or components used in the rolling powder are too expensive or must be used in large quantities.
Thus, there remains a need for rolling powders useful in the manufacture of chewing gum, which avoid these drawbacks and which provide a finished chewing gum product wherein the rolling powder does not adversely affect the taste, mouth feel, or processing properties of the gum.